Subject: [RFC 17/23] ARM: add machine desc hook for early memory/paging initialization

From: [email-masked] (Arnd Bergmann)
Date: Tue, 24 Jul 2012 14:32:27 +0000

On Tuesday 24 July 2012, Cyril Chemparathy wrote:
> diff --git a/arch/arm/include/asm/mach/arch.h b/arch/arm/include/asm/mach/arch.h
> index 0b1c94b..49e9c2a 100644
> --- a/arch/arm/include/asm/mach/arch.h
> +++ b/arch/arm/include/asm/mach/arch.h
> @@ -39,6 +39,7 @@ struct machine_desc {
>                                          struct meminfo *);
>         void                    (*reserve)(void);/* reserve mem blocks  */
>         void                    (*map_io)(void);/* IO mapping function  */
> +       void                    (*init_meminfo)(void);
>         void                    (*init_early)(void);
>         void                    (*init_irq)(void);
>         struct sys_timer        *timer;         /* system tick timer    */
> diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
> index e15d83b..7cbe292 100644
> --- a/arch/arm/kernel/setup.c
> +++ b/arch/arm/kernel/setup.c
> @@ -964,6 +964,9 @@ void __init setup_arch(char **cmdline_p)
>  
>         parse_early_param();
>  
> +       if (mdesc->init_meminfo)
> +               mdesc->init_meminfo();
> +
>         sort(&meminfo.bank, meminfo.nr_banks, sizeof(meminfo.bank[0]), meminfo_cmp, NULL);
>         sanity_check_meminfo();
>         arm_memblock_init(&meminfo, mdesc);

The function pointers in that structure are ordered by execution time,
and you call init_meminfo just before ->reserve, so it should go there.

I wonder if it's better to just do the setup in the reserve callback,
which would be a slight abuse of that interface but also keep down
the number of early callbacks.

	Arnd